At present, touch screens are mainly divided into capacitive touch screens, resistive touch screens, infrared touch screens, acoustic touch screens and near field imaging (NFI) touch screens. Due to advantages of portability, easy accessibility and the like, touch screens have become indispensable parts of hand-held terminals such as mobile phones, tablet computers and personal digital assistants, and are increasingly used in products such as notebook computers and desktop computers. Therefore, there are demands for continuously improving the performance of the touch screen.